Principle that L of EEF discharges and employing analyzing

First, preface EEFL is a externally positioned electrode fluorescent lamp External Electrode Fluorescent Lamp Abbreviation,its structural features is been at modulator tube been last electrode,there are intraductal except filling with gas of job and interior surface and coating with the fluorogenic power layer on glass, can be said to be the root ” The empty tube ” . The intersection of EEFL and the intersection of glass tube and the intersection of appearance and the intersection of bread and naked a layer of conducting layers or metal clutch of both ends, form and discharge to the modulator tube the external electrode with big influence, the name of EEFL also comes from this.

Fig. 1. Basic structural representation of EEFL A glass tube Fluorogenic power layer of 2 three-primary colors 3 external electrodes 4 job gas Ne, Ar, Hg gas mixture In order to have a more ocularly knowledge of structure and characteristic characteristic of EEFL, let us do several experiments first. Fetch the glass tube of a diameter 3mm, come down through normal exhaust air technique and sealing off after filling with 80 torrs of neon, it seems that this is really a clean and bright one ” Empty ” Glass tube. Both ends of the transparent glass tube here, a layer of aluminium foil of outer surface parcel of glass tube is stuck closely, then link the aluminium foil of this glass tube of both ends with cold cathode fluorescence lamp CCFL Ausgang of the inverter, as the mains switch opens, lighted inner neon of glass tube and discharged and emitted the bright reddish shade immediately, like a pin neon bulb. In fact, we can say this is a externally positioned electrode neon bulb. If change the inner aeration of above-mentioned glass tube into Ne, Ar, Hg gas mixture, and will plate a layer of fluorogenic power layer on the inboard wall of glass tube, the above-mentioned externally positioned electrode neon bulb has been turned into a externally positioned electrode fluorescent lamp EEFL. Link Ausgang and its external electrode of the corresponding CCFL inverter power, can light but shiny like CCFL. In fact, any fluorescent lamp, after the conducting layer forms the external electrode on the both ends appearance bread of glass tube, form EEFL of a certain type, can light by exporting 1- 3 kilovolts of high-frequency power. Therefore, EEFL actually and between us distance is the proximity like this! Through above-mentioned, make us feel the first overhanging characteristic of EEFL practically, that is that structure is simple, the craft is simple and convenient, the cost is lower. EEFL second overhanging characteristic is electrical properties, that is that EEFL modulator tube can be used in parallel directly, namely connect the ignition point in parallel directly. When needing to light polyrhizal EEFL at the same time ‘ For instance, LCD colored video direct backlight source ,Often only need to drive the power to light between several and several dozen EEFLs directly with a high frequency, therefore it is very simple and convenient to use and the cost is lower. Notice, almost all the gas discharge lamps can’t be used in parallel directly, rare EEFL gives us a facility like this! Besides the aforesaid, many materials report EEFL have luminance and life-span more more than CCFL also, therefore think EEFL is the product of CCFL technical progress, will rise at the beginning of the 21st century and replace the new light source of CCFL soon. Is EEFL really good and cheap and replacing more CCFL soon than CCFL? By the look of real development in recent years, it is not like this yet at present. Though people are interested in EEFL very much and expect, it is really many that trial-produce and try out the enterprises of EEFL, but is still at trying out stage so far, its volume of production and marketing can’t compare with CCFL far. Why? Because consistency of performance and stability of China EEFL products are not good enough, especially EEFL drives the power to expect relatively much to its related high frequency, a lot of can not meet instructions for use but can’t use normally in the existing products. So, the development of EEFL faces the problem that the technology of modulator tube and related circuit two respect needs further improving at present.

Principle of the discharging of second, EEFL It is the convenience like this that EEFL structure is so simple, lights and uses in parallel so easily and directly, make people germinate the interest once exposed to iting, want to ask an outcome, in addition the task of present improvement EEFL characteristic is extremely urgent, so, the ones that clarify EEFL discharge the research of the principle can’t already be avoided conscientiously. Only know the basic process of gas discharge in EEFL correctly, proceed from group concept to improve structure and craft of EEFL, will receive the good effect. But,at what has been seen about EEFL at thesis materials,it is always area at not lasting principling of discharging of EEFL but, there are only several sentences of general words, the precise analysis and describing without comparison. For example, some only mention it is the electromagnetic induction that discharge electrodelessly, like well known electrodeless fluorescent lamp, this is obviously wrong. Can respond to and produce the high-frequency electric field sufficient to light and discharge because EEFL may not have very strong high-frequency magnetic field through the modulator tube; Some mention it is the high-frequency electric field that causes intraductal gas discharge through EEFL external electrode and tube wall capacitive coupling the input modulator tube, belong to high-frequencily and electrodelessly and discharge; Some are regarded as the gas discharge that is produced with the high-frequency voltage to the external electrode through glass medium, it is the barrier layer of medium that discharges etc. electrodelessly. Until ” whether whom all electrode does not expose to ionized gas discharge way call discharging electrodelessly” Definition,it is EEFL intraductal it install electrode,only last external electrodes external outside glass tube both ends, it seems that it is blameless to belong to discharging electrodelessly. However, analyse in depth the gas discharge course that EEFL takes place and find the electrode course still keeps EEFL high frequency discharge can’t be few, particularly EEFL still launches the electronic negative pole, accelerated electron, exactly ionic negative pole potential drop. In order to explain this, let us review the analysis on high frequency discharge several kinds of situations of the gas discharge theory. The discharge that the gas produces under encouragement of high-frequency energy is called high frequency discharge, its current density j is: j =[Nee2 / me 2 2 ]E 1 E electric field intensity in the type, high-frequency angular frequency of electric field, is the effective collision frequency of electron, is calculated by the following formula: =3.19* 109* P/ Te0.5 2 P is the atmospheric pressure mm Hg in the type ,Te is the electron temperature K . Have the intersection of collision frequency and relation size of more effective according to high-frequency the intersection of electric field and the intersection of angular frequency and and electron, high frequency discharge can be divided into <<? ???? ??